Lubricated plug valve assemblies



Oct. 18, 1966 J. w. BELL ETAL 3,279,492

LUBRICATED PLUG VALVE ASSEMBLIES Original 'i led Nov. 30, 1959 5Sheets-Sheet 1 INVENTORS J05 W5! Afwww/ 511m? Oct. 18, 1966 J. w. BELLETAL 3,279,492

LUBRICATED PLUG VALVE ASSEMBLIES Original Filed Nov. 30, 1959 5Sheets-Sheet 2 INVENTOR 5 4 J0: [Vial ATTORNEY6 Oct. 18, 1966 J. w. BELLETAL LUBRICATED PLUG VALVE ASSEMBLIES 5 Sheets-Sheet 5 Original FiledNovl 30, 1959 ATTOR Oct. 18, 1966 J. w. BELL ETAL LUBRICATED PLUG VALVEASSEMBLIES 5 Sheets$heet 4 Original Filed Nov. 50, 1959 ATTORNEY Oct.18, 1966 J. w. BELL ETAL 3,279,492

' LUBRICATED PLUG VALVE ASSEMBLIES Original Filed Nov. 30, 1959 5Sheets-Sheet 5 i 9 J5 INVENTORS (/0: /7Aw 40,415 in BY WW W ATTORNEYSUnited States Patent "Ce 3,279,492 LUBRICATED PLUG VALVE ASSEMBLIES JoeW. Bell, Sulphur Springs, Tex., and Herman H.

Fowler, Kearney, Nelm, assignors to Rockwell Manufacturing Company,Pittsburgh, Pa., a corporation of Pennsylvania Original application Nov.30, 1959, Ser. No. 856 ,2 65, now Patent No. 3,139,906, dated July 7,1964. Divided and this application Apr. 4, 1962, Ser. No. 185,164

Claims. (Cl. 137-246.].4)

This is a division of Serial No. 856,265, filed November 30, 1959, forValve Assemblies, and since matured into US. Letters Patent No.3,139,906, dated July 7, 1964.

The present invention relates to valves and more particularly to dualcompletion plug valve assemblies as used in Christmas tree constructionsor other well-completion equipment.

A preferred application of the present invention is in connection withdual completion oil or gas wells having parallel nonconcentric tubingstrings wherein the dual tubing strings are positioned parallel andclose together in the well in order to obtain production from differentstrata. It is desirable to maintain the tubings strings thus relativelypositioned and as close together as possible in the lower well head andthe upper well head or Christmas tree structure to reduce the costs ofdrilling and also in order that formation testing tools and the like maybe introduced into the tubing strings through the well head andChristmas tree equipment.

It will be appreciated, however, that the minimal lateral distancebetween the centerlines of the parallel tubing strings is limited by thewell head valve structures interconnecting the Christmas tree structureor upper well head with the lower well head or Well casing forcontrolling fiuid flow through the tubing strings. This is so becausethe well head valves controlling the flow of fluid through the tubingstrings must be constructed to withstand well pressures and also must becapable of non interfering valve operation.

In the past it has been the custom to control the fluid flow through theparallel tubing strings by a conventional dual completion plug valveassembly wherein the valve body is formed with straight parallel spacedaxial through passages separated by a common wall. The valve assembly isgenerally mounted between a tubing string head mounted on the wellcasing and the upper Christmas tree casing and is connected to thetubing strings so that the through flow passages in the valve body arecoaxial with the tubing strings and the flow passages formed in theupper Christmas tree casing. The axial through passages of the valvebody are intersected at right angles at different levels by valve plugseating cross bores aligned with the center line of the through passagesand, consequently, the tubing strings. A conventional valve plug whereinthe axis of plug rotation aligns with the axis of the plug port isrotatably mounted on each of the seating surfaces provided by the crossbores so that each plug has its rotational axis and through port axis inalignment with its associated cross bore and through passage forcontrolling the flow of fluid therethrough.

The minimum lateral distance obtainable between the center lines of thefluid flow passages in the conventional dual plug valve body andconsequently the tubing strings for a given internal fluid flowpassageway diameter is principally determined by the thickness of thecommon wall separating the passages which has a critical minimalthickness in a plane passing through the longitudinal axes of bothpassages and measured transverse to the longitudinal axes of the crossbores. The thickness of the common wall in this plane, it will beappreciated, is reduced by the formation of the valve seating cross boreand con- 3,279,492 Patented Oct. 18, 1966 sequently the smallestcritical common wall thickness corresponds to the distance betweenopposed wall surfaces of the common wall measured in this planelaterally along the transverse axis of one of the cross bores. Thisminimum critical common wall thickness must always be of such magnitudeto safely withstand the maximum well pressures to which the valve is tobe subjected. It is equally clear that the fixed lateral distancebetween the axis of one cross-bore associated with one passage and thelongitudinal axis of the other through passage therefore corresponds tothe radius of the cross bore measured in the plane passing through thelongitudinal axes of both through passages, plus the critical commonwall thickness measured laterally in this plane along the transverseaxis of the cross bore, and plus the radius of the other throughpassage.

In the valve body of a conventional dual-completion plug valve asdescribed above, the axis of the cross bore is coincident with thelongitudinal axis of its associated through passage. Consequently,lateral distance between the axes of the through passages in theconventional valve body and, therefore, the axes of the tubing stringsis fixed by the radius of the cross bore intersecting one throughpassage, the critical common wall thickness and the radius of the otherthrough passage, all measured laterally in a plane passing thelongitudinal axes of 'boththrough passages.

The structure incorporating the preferred embodiment of the invention isillustrated as a dual plug valve assembly for controlling the flow offluid through the lower well head tubing strings wherein the throughflow passages of the valve body are positioned closer together tothereby facilitate a closer positioning of the tubing string while atthe same time maintaining coaxial alignment of the valve body flowpassages with the tubing strings. This is accom lished essentially bylaterally offsetting the rotational axis of the plug outwardly from thelongitudinal axis of its associated through flow passage and away fromthe-common dividing wall so as to reduce the depth of the recess formedin one side of the valve body as a result of machining the seating boreby the amount of offset. By this structure, the lateral distance betweenthe axes of the through flow passages in the valve body and between theaxes of the tubing strings is equivalent to the fixed lateral distancein a conventional dual plug valve less the amount of offset of eachplug. Thus, the lateral distance between the through flow passages isreduced by an amount corresponding to the offset of the cross bore andthe valve plug so as to enable the tubing strings to be correspondinglymoved closer together.

In order to maintain an alignment of the plug port with the valve bodyflow passage, the preferred embodiment comprises a further associatedfeature in that the through ports of the laterally offset plugs arelaterally offset with respect to the axis of rotation of the plug towardthe common dividing wall so that the plug ports axially align with thethrough fluid flow passages of the valve body when the plug is in openposition. By this construction, parallel axial passages are providedfrom the tubing strings in the lower well head to the upper well headChristmas tree structure.

The present application claims novel plug valve and associated seatingsurface grooving arrangements per se and in the novel dual completionvalve assembly.

The major object of this invention is to provide a plug valve assemblyhaving novel lubricant grooving in the plug and body seating surfaces.

Another object of the present invention is to provide a novel lubricatedplug valve assembly having arotatable ported plug wherein a set oflongitudinal grooves are provided including a single long longitudinalgroove in con- 3 stant communication with a lubricant chamber andremaining unexposed to line fluid throughout normal plug rotation andtwo short longitudinal grooves are adapted to be connected to thelubricant chamber at fully opened and fully closed valve positions only.

Still a further object of the present invention is to provide a novelplug valve assembly having a body and a plug rotatably mounted in avalve body seating bore about an axis that is laterally otfset withrespect to the longitudinal axis of a through fluid flow passageintersecting the seating bore wherein the valve body and plug seatingsurfaces are provided with special lubricant grooving.

Another object of the present invention is to provide a novel plug valveassembly that is lubricated and is adapted to rotate an angular distanceof more than 90 between fully opened and fully closed positions andincorporates special lubricant passages.

Further objects of the invention will presently appear as thedescription proceeds in connection with the appended claims and theannexed drawings wherein:

FIGURE 1 is a plan view showing a plug valve assembly according to oneembodiment of the present invention;

FIGURE 2 is a section substantially along line 22 of FIGURE 1illustrating the valve body with the valve plug removed;

FIGURE 3 is a section substantially along line 3-3 of FIGURE 2;

FIGURE 4 is an enlarged sectional view along line 44 of FIGURE 1;

FIGURE 5 is a developed view of the valve body seating surface for theplug valve assembly illustrated in FIG- URE 1, showing lubricantgrooving;

FIGURE 6 is an enlarged fragmentary sectional view substantially alongline 66 of FIGURE 4 and showing the valve plug in fully opened position;

FIGURE 7 is a view similar to FIGURE 6 but showing the valve plug infully closed position;

FIGURE 8 is an enlarged elevational view of a valve plug for the valveassembly illustrated in FIGURE 1, showing the plug surface grooving;

FIGURE 9 is a section substantially along line 9? of FIGURE 8;

FIGURE 10 is a plan view showing a plug valve assembly according to afurther embodiment of the present invention;

FIGURE 11 is a section substantially along line 11-11 of FIGURE 10; and

FIGURE 12 is a section substantially along line 1212 of FIGURE 11.

Referring now to the drawings, and more particularly to FIGURES 1-3, thereference numeral generally designates a dual completion plug valveassembly comprising a valve body 21 formed with spaced parallel axialthrough fluid flow passages 22 and 24 and having end flanges 26 and 27by which valve 20 is adapted to be fixedly secured at its lower end tolower well head equipment (not shown) and at its upper end to an upperwell head or Christmas tree structure (not shown). As best shown inFIGURES 2 and 3, the fluid flow passages 22 and 24 are respectivelyintersected at diiferent levels and at might angles by tapered valveseating bores 30 and 32 which are both open at their opposite ends. Inaccordance with the present invention, the longitudinal axes 28 and 29of the bores 30 and 32 are laterally and outwardly offset with respectto the longitudinal axes 28a and 29a of their respective fluid flowpassages 22 and 24 so that axes 28a and 29a are closer to the commonwall portion 33 dividing passages 22 and 24.

The two sides of the valve 20 are identical, and the detaileddescription will be limited to only one side but will be equallyapplicable to both. Identical reference numerals refer to identicalelements of the valves on both sides.

Thus, with reference to FIGURES 1-4, a tapered valve 'or the like.

plug 34 is rotatably seated on the conical surfaces provided by each ofthe valve seating bores 30 and 32 and is provided with a diametricalthrough port 36 shown in its fully open position in FIGURE 4 and adaptedto be rotated to a fully closed position about an axis coincident withlongitudinal bore axis 29. The through port 36 of each valve plug 34, inaccordance with the present invention, is oiiset laterally and inwardlywith respect to the axis of plug rotation by a magnitude equal to theoffset of the plug axis.

By this construction, each port 36 is positioned so as to axially alignwith its associated fluid flow passage 22 or 24 when the plug is rotatedto its valve open position to thereby establish uninterrupted coaxialcontinuations of passages 22 and 24. Thus, it will be appreciated thatby laterally offsetting the longitudinal axes of cross bores 30 and 32outwardly from the axes of their respective fluid flow passages 22 and24, the lateral dimension 37 (FIG- URE 3) of the recess formed in commonwall 33 by the formation of each cross bore is reduced by a magnitudecorresponding to the ofiset of the cross bores. This serves to reducethe over-all lateral thickness of common Wall portion 33 between thepassages 22 and 24 as indicated at 38 (FIGURE 3) thereby permitting thepassages 22 and 24 to be more closely spaced together. The tubingstrings (not shown) in the lower well head (not shown), to which valveassembly 20 is adapted to be secured, axially align with passages 22 and24 and are thereby correspondingly more closely spaced together in thewell. This, among other advantages, serves to reduce the minimaldiameter of the well hole to be drilled for accommodating the lower wellhead and the tubing strings.

By oiisetting the through ports 36 of valve plugs 34 with respect to theplug rotation-a1 axis so as to coaxially align with the fluid flowpassages 22 and 24, it is equally clear that parallel uninterruptedaxial fluid flow passages are obtained extending from the upper wellhead Christmas tree structure (not shown) and through the valve assemblyand lower well head.

As best shown in FIGURE 4, valve body 21 at the smaller end of each ofcross-bores 30 and 32 is extended at 40 and has a threaded hole 42 boredand tapped therethrough extending from the exterior of the valve to thelubricant chamber 44 provided at the smaller end of the plug 34. Anoperating valve stem 45 squared at its outer end has a threaded portion48 extending through bore 42 coaxial with the rotational axis of plug 34and is provided at its inner end with a tongue or extension 50, thepurpose of which will hereinafter appear. The threaded porton 48 of stem46 has accurately machined running threads which cooperate with thethreads in the Wall of hole 42.

Tapered plug 34, forming one wall of lubricant chamber 44, extendspartly into this chamber and is connected to stem 46 by an Oldharn typecoupling comprising a tongue 52 integrally formed at its smaller end. Anequalizer block 54 having a diametrical groove 56 shaped correspondinglyto the tongue 52 projecting into groove 56. A hole 58 of generallyrectangular shape is formed axially through equalizer 54, and inassembled position the tongue 50 of stem 46 is freely received in hole58 with a small amount of play.

With continued reference to FIGURE 4, an indicator stop collar 60 isfixedly secured to the squared end of stem 46 by any suitable means anda stop lug 62 integrally depending from collar 60 cooperates withstopab-utment members 64 and 6-6 on valve body 21 to limit rotation ofthe valve plug 34 to a turn of 100.

At the larger end of plug seating bore 32, valve body 21 is providedwith a threaded bore 70 formed coaxially with tapered bore 32 as bestshown in FIGURE 4. A threaded plug or closure member 72 t-hreadedlyengaged in bore 7% has a non-circular end 74 extending beyond valve body21 by which it may be rotated by a wrench The threads at the jointbetween the closure plug 72 and the valve body 21 are preferably of thetype having at least one face substantially normal to the axis of theplug 72 with the apex angle thereof being received as required.

Threaded plug 72 has a central threaded bore 76 in which is threaded aplug adjustment screw member 78, the threaded joint between the plug andadjustment screw being sealed by packing in a suitable annular groove orrecess 180a- Packing is supplied to the annular packing groove 80through a bore 81 and radial ducts 82 in adjustment screw 78. A checkvalve fitting 83 is threaded into bore 81 and carries a spring pressedball check valve (not shown) to prevent refluxing of the packing. Thepacking in recess 80 is compressed by means of a plunger '86 threadedinto a hole 87 in check valve fitting 83.

The larger end of valve plug 34 is formed with a recess 88 in which aplate 90 is suitably supported to engage a thrust ball 92. Thrust ball92 is held in position in a conical recess 94 in plate 90 by a thrustdisc 96- bearing against adjustment screw 78 whereby rotation of thescrew 78 adjusts the seating pressure of plug 34 on its seat.

By this construction it will be appreciated that the larger end of theseat is closed by the threaded plug 72 and is sealed by a tapered ringgasket 98 compressed between the upper beveled end of threaded plug 72and valve body 21.

In order to seal and lubricate the surfaces between valve plug 34 andthe body, a suitable lubricant is introduced into chamber 44 through theoperating stem 46 which is provided with a threaded bore 100 extendingaxially therethrough and in which a suitable check valve fitting (notshown) is located to prevent reflux of lubricant. A threaded screw 102is threadedly engaged in how 100 at the exposed end of the stem 46. Thisscrew 102 when rotated in the bore 100 functions to exert pressure onlubricant in bore 100' to thereby push it through the check valve (notshown) and chamber 44 to the plug valve seating grooves to be described.

Because of a close sealing fit provided between the stem threadedsection 48 and the threaded bore 42 outward flow of lubricant fromchamber 44 is resisted so that the lubricant between these threads forma primary seal.

At the smaller end of the plug 34, a secondary seal comprising a packingchamber 106 containing packing 108 under pressure around the threadedsection 48 of stem 46 is provided to prevent outward escape oflubricant. Any suitable fibrous packing material can be used for thispurpose, such as a stiff mixture of lubricant, graphite or asbestos, orthe like. Packing is supplied to the packing chamber 106 through apassage 109 in the side of valve body 21. A check valve fitting 110threaded into the passage 109 carries a spring pressed check valve 114to prevent refluxing of packing therefrom. A threaded compressionplunger 116' threaded into a bore 118 in the check valve fitting 110serves to compress the packing in passage 109 and supply it to thepacking chamber 106. A bore 120 into which a pipe plug 122 is threadedlyengaged communicates with packing chamber 106 opposite passage 112 toprovide for removal of packing from chamber 106.

In order to supply and distribute lubricant over the seating surfaces ofthe body and plug 34 from the cham ber 44, the plug seating bore 32 isprovided with parallel circumferential grooves 130 and 132, one adjacenteach end of the plug 34 as best shown in FIGURES 2 and 5.Circumferential groove 130- adjacent the smaller end of plug 34 isalways connected to the lubricant chamber 44 by a series of fourci-rcumferentially spaced longitudinally extending dwarf grooves 134,136, 138 and 140 (FIGURE 5) provided in the seating surface 32 of thevalve body 21 and extending downwardly beyond groove 130.

Referring now to FIIGURES 2, 5 and 6, dwarf grooves 136 and 138 arelocated on the side of the fluid passage 24 nearest to the rotationalaxis 29 of the plug and are spaced apart. Dwarf grooves 134 and locatedon the other side of passage 24 are respectively spaced 100 from dwarfgrooves 136 and 138 so that the angular distance between grooves 134 and140 is substantially 60. Both dwarf grooves 136 and 138 are angularlyspaced 40 from an axis passing through the rotational center of the plugand extending parallel to the longitudinal axis of passage 24.

Annular groove 132 adjacent the larger end of the plug 34 connects to aseries of four upwardly extending dwarf grooves 142, 144, 146 and 148(FIGURES 2 and 5) provided in the seating surface 32 and respectivelyaligned with the dwarf grooves 134, 136, 138 and 140 adjacent thesmaller end of plug 34.

Referring now to FIGURES 4, 8 and 9, a circumferential groove 150 isprovided in plug 34 adjacent the smaller end thereof directly oppositecircumferential groove 130. Plug 34 is provided with a furthercircumferential groove 152 adjacent the larger end thereof and directlyopposite circumferential body groove 132. Between annular grooves 150'and 152, a series of two short longitudinal grooves 154 and 156 and along longitudinal groove 158 are provided in the plug surface. As bestshown in FIGURE 8, short longitudinal grooves 154 and 156 terminateshort of both annular grooves 150 and 152 while long longitudinal groove15 8 connects to upper annular groove 150 and terminates short of lowerannular groove 152.

With continued reference to FIGURES 8 and 9, long longitudinal groove158 and short longitudinal groove 154 are located on the side of theplug port 36 nearest to the rotational axis of the plug and are spaced1.00" apart. Grooves 154 and 158 are respectively positioned adjacentopposed ends of plug port 36 so as to overlap grooves 138 and 136 inseating surface 32 when port 36 aligns with passageway 24 in valve openposition. The other short longitudinal groove 156 is located on theopposite side of plug port 36 from grooves 154 and 158 and is spaced 100from the long longitudinal groove 158 .so that long groove 158 is spacedequiangularly between the two short grooves 154 and 156.

Referring now to FIGURE 6, the valve is shown in opened position whereinlong longitudinal plug groove 158 overlaps dwarf grooves 136 and 144.Short longitudinal plug groove 154, in valve open position, overlapsdwarf grooves 138 and 146, while short plug groove 156 overlaps dwarfgrooves 134 and 142.

Assuming the direction of flow to be as shown by the arrow in FIGURE 7,to close the valve plug 34 is rotated in a clockwise direction as bestshown in FIGURE 7, and reaches fully closed position after rotating 100.Now long longitudinal groove 158.0verlaps dwarf grooves 138 and 146. Inthis position, short groove 154 overlaps dwarf grooves 140 and 148 andshort groove156overlaps dwarf grooves 136 and 144.

During rotation of valve plug 34 between open and closed positions, itwill be appreciated that short longitudinal grooves 154 and 156 areexposed to line fluid in passing from one position to the otherposition. These short grooves 154 and 156, however, are disconnectedfrom their associated dwarf grooves and therefore from the lubricantchamber 44 during rotation of the plug and are only connected to thelubricant chamber 44 when the valve is in fully open or fully closedpositions. This serves to prevent escape of pressurized lubricant fromthe chamber 44 at such times when longitudinal grooves 154 and 156 areexposed to line fluid. Further, it will be seen by reference to FIGURES6 and 7 that long longitudinal groove 158, which is continuallyconnected to lubricant chamber 44, moves only along valve plug seatingsurface 32 on one Side of the passage 24 and is not exposed to directimpingement of line fluid in passing between open and closed valvepositions.

With continued reference to FIGURES 6 and 7, it will be appreciated thatas a result of laterally offsetting the rotational axis of plug 34 fromthe axes of port 36 and the passage 24, plug port 36 is in constantcommunication with the upstream end of passage 24 both in opened andclosed positions.

As best shown in FIGURE 4, a chamber 160 is formed at the larger end ofplug 34 between plate 90 and closure plug 72. Passages 161 and 162 inplug 34 and plate 90 respectively may be provided, connecting port 36with chamber 160 to prevent the entrapment of incompressible lubricantor line fluid in chamber 160 which would interfere with jacking the plugfrom its seat. These passages 161 and 162 permit the escape ofincompressible fluid from chamber 160 when plug 34 is jacked from itsseat by lubricant pressure, and may be omitted under certain conditions.

In operation of the valve, one or more sticks of lubricant areintroduced into threaded bore 100 in stem 46 and lubricant is forced byrotation of threaded screw 102 into lubricant chamber 44 until thechamber is filled. Since dwarf grooves 134, 136, 138 and 140 alwayscommunicate with lubricant chamber 44, they also become filled withlubricant. Lubricant is transmitted from dwarf grooves 134, 136, 138 and140 of circumferential grooves 130 and 150 and then to long longitudinalplug groove 158 which is connected to circumferential groove 150.Lubricant from lubricant chamber 44 also flows between threads 42 and 48to seal stem 46 and to prevent binding thereof.

The adjustment screw member 78 is adjusted to develop the proper seatingthrust on the plug 34 and sufficient pressure can be developed on thelubricant in chamber 44 to jack the plug from its seat when required.

As shown in FIGURE 6, the valve is in open position and lubricant istransmitted through dwarf grooves 134, 136, and 138 to longitudinal pluggrooves 154, 156 and 158. Lubricant passes from the longitudinal pluggrooves through overlapping dwarf grooves 142, 144 and 146 (FIGURE tothe lower circumferential grooves 132 and 152. An increase in lubricantpressure in chamber 44 and in the grooves in the plug and body seatingsurfaces will result in axial displacement of plug 34 relative to thetapered bore.

In order to close the valve, stem 46 is turned clockwise as viewed fromFIGURES 6 and 7 and the thrust of tongue 50 against the walls of groove58 in equalizer 54 is transmitted by the tongue and groove connection 52and 56 to the plug, the turning force being centered and balanced by theequalizer.

While turning plug 34, short longitudinal grooves 154 and 156 aredisconnected from the source of lubricant by reason of their separationfrom dwarf grooves 134 and 138. Thus, exposure of grooves 154 and 156 toline fluid does not wash lubricant out of any part of the lubricantsystem other than the grooves 154 and 156, which may be readily refilledwhen the plug is in either fully open or fully closed position.

In fully closed position, as shown in FIGURE 7, passage 24 is surroundedby a substantially complete seal in substantially the same way as in thefull open position. Lubricant, in the closed position, is allowed topass through longitudinal grooves 154, 156 and through dwarf grooves142, 144 and 148 to the circumferential lower grooves 132 and 152.

It will be noted that when the valve is open as in FIGURE 6, acontinuous circuit of grooving in the plug and body surfaces surroundsthe openings of passage 24 into bore 32, and when the valve is closed asin FIGURE 7, a complete circuit of grooving in the plug and bodysurfaces surrounds the upstream opening of passage 24 into bore 32.

A further embodiment of the present invention is illustrated in FIGURES-12, wherein flow through parallel non-concentric tubing strings 170 and172 is controlled by separate valve assemblies 174 and 176. Both of theValve assemblies 174 and 176 are identical and the detailed descriptionwill be limited to only one but will be equally applicable to both.

Thus, with continued reference to FIGURES 10 12, valve assembly 174 isshown to comprise a valve body 178 having an enlarged central portion189 integrally interposed between coaxially opposed annular end sections182 and 184 connecting to tubing string and defining a straight throughfluid flow passage 186 extending coaxially with the tubing string. Aninverted tapered cross bore 187 open at both ends and intersecting thefluid flow passage 186 at right angles is machined in the enlarged valvebody portion and has its longitudinal axis 188 laterally offset withrespect to the longitudinal axis 190 of passage 186 outwardly and awayfrom tubing string 172.

Valve body portion 180 is generally conically shaped to correspond tothe tapered cross bore 187 and is protuberant with respect to theadjacent end sections 182 and 184 as is commonly provided for inconventional plug valve casings. When separate conventional plug valveshaving casings of the above-described configuration are used to controlfluid flow through parallel non-concentric tubing strings, it will beappreciated that the conventional shape of the valve casings will limitthe proximate spacing of the tubing strings.

In accordance with the present invention, a longitudinally extendingfurrow-shaped recess 192 having a smooth arcuate surface is provided inthe side of valve body 178 facing tubing string .172. The center ofcurvature of recess 192 is designated at 194 and is approximatelycoincident with the center of tubing string 172, in a horizontal planepassing through the axes of passage 186 and tubing string 172 as viewedfrom FIGURE 11. Preferably, recess 192 has a greater radius than theoutside radius of tubing 'string 172 so as to provide for a clearancebetween the wall of recess 192 and the outer periphery of tubing string172.

Rotatably seated in cross-bore 18 7 is a tapered valve plug 196 having adiametrical through port 198 shown in its open position in FIGURE 12 andlaterally offset with respect to the axis of plug rotation toward therecessed side of valve casing 178. The magnitude which port 198 isoffset from the rotational axis of plug 196- is mounted in seating bore187 and rotated to opened position. By this construction, it will beappreciated that in opened position port 198 provides a smoothuninterrupted flow passage through valve casing 178 to facilitate flowof fluid through tubing string 179.

Since plus seating bore 187 is shifted laterally away from tubing string172, in accordance with the present invention, and outwardly withrespect to the axis of fluid passage 186, the lateral distance indicatedat 201 is reduced by a magnitude corresponding to the magnitude by whichplug 196 is offset. Thus, by this structure, tubing string 172 can bemore closely positioned to tubing string 170 in comparison toconventional plug valve assemblies.

The construction of plug 196 and the lubricating system therefor isidentical to the embodiment described in connection with FIGURES 1-9with two exceptions relating to the construction of the valve pluglubricating system.

As best shown in FIGURE 11, one exception is that valve plug 196 has nocircumferential groove adjacent its smaller end as compared to the valveplug 34 of FIG- URES l-9 and the long longitudinal groove 1 58 isextended to the end of valve plug 196 so that it communicates directlywith lubricant chamber 44. Also there is of course no correspondingcircumferential body groove 130, upper dwarf grooves 134, 136, 138 and140, however, being retained and opening at their ends into chamber 44.

The second exception is that plug longitudinal grooves 158 and 154 arespaced apart by an angular magnitude of 104 as compared to the 100spacing in the embodiment of FIGURES 1-9. Similarly, longitudinal pluggroove 156 is spaced 104 from longitudinal plug groove 158. Dwarfgrooves 134, 136, 138 and 140 adjacent the smaller end arecorrespondingly positioned in plug seating bore 187 to align withlongitudinal plug grooves 154, 156 and 158 as described in theembodiment of FIGURES l9. That is, dwarf grooves 136 and 138 are spaced104 apart and dwarf grooves 134 and 140 are also spaced 104 apart.Similarly, plug seat dwarf grooves 142, 144, 146, 148 adjacent thelarger end of plug 196 are correspondingly angularly spaced apart sothat the operation of valve 174 is the same as that of valve of FIGURES1-9.

Thus, by this structure, it will be appreciated that plug 196 of valve174 is rotatable through an angular distance of 104 between opened andclosed positions.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. In a plug valve assembly characterized by a through passage for fluidflow intersected by a plug seating bore, a ported plug rotatably mountedin said bore for movement between a fully closed position where itblocks fluid flow through said passage and a fully open position wherethe plug port is aligned with said passage, the axis of rotation of saidplug being laterally oflset with respect to the axis of said passage,and said plug having a straight through port the longitudinal axis ofwhich is offset with respect to the axis of rotation of said plug toalign said port with said passage in valve open position, meansproviding a body of fluent lubricant in said assembly, a system ofgrooving in the seating surfaces of said plug and body extendingcontinuously around the intersection of said passage and bore at leastat one side of said bore in both fully open and fully closed positionsof said plug, said system comprising three circumferentially spacedlongitudinal grooves in the plug surface, one of said grooves beinglarger than the other two and continuously connected in communicationwith said lubricant body and the other two grooves being disconnectedfrom communication with said lubricant body except in valve open andclosed positions of the plug, said other two grooves being disposed atopposite sides of the plug port from each other and being equallycircumferentially spaced relative to said longer groove an angulardistance greater than 90, means connecting said system to receivelubricant from said body of fiucnt lubricant, and means for interruptingthe continuity of said system of grooving as the plug is rotatingbetween said positions.

2. In a plug valve assembly characterized by a through fluid flowpassage intersected by a plug seating bore having an axis offsetlaterally with respect to the axis of said passage, a ported plugrotatably mounted in said bore for movement between a fully closedposition where the plug blocks fluid flow through said passage and afully open position where the plug port is aligned with said passage,said plug having a straight through port offset from the axis of saidbore so as to align with said passage in valve open position of saidplug, means providing a body of lubricant in said bore adjacent one endof the plug in the assembly, a plurality of circumferentially spaceddwarf grooves in the surface of said bore at said one end all incommunication with said body of lubricant, a similar plurality of dwarfgrooves at the other end of said bore, circumferential grooving in theseating surface of the plug and body at said other end of said boreconnecting all of said lower dwarf grooves, and three circumferentiallyspaced longitudinal grooves on the surface of said plug, one of saidlongitudinal grooves being long enough to communicate with said body oflubricant in all positions of rotation of said plug and the other two ofsaid grooves being shorter than said one longitudinal groove with bothshort grooves terminating short of opposite ends of the plug and beingadapted to extend between and interconnect aligned pairs of upper andlower dwarf grooves only in the fully open and fully closed positions ofthe plug, said other two grooves being substantially equallycircumferentially spaced from said one groove an angular distancegreater than and being disposed at opposite sides of said plug port fromeach other.

3. In a plug valve assembly characterized by a through fluid flowpassage intersected by a plug seating bore having an axis offsetlaterally with respect to the axis of said passage, a plug having anoffset port therethrough rotatably mounted in said bore for movementbetween a fully closed position where the plug blocks fluid flow throughsaid passage and a fully open position where the plug port is alignedwith said passage, means providing a body of lubricant in said boreadjacent one end of the plug in the assembly, four circumferentiallyspaced dwarf grooves in the surface of said bore at said one end all incommunication with said body of lubricant, a similar plurality of dwarfgrooves at the other end of said bore, circumferential grooving in theseating surface of the plug and body at said other end of said boreconnecting all of said lower dwarf grooves, and three circumferentiallyspaced longitudinal grooves on the surface of said plug, one of saidlongitudinal grooves being long enough to communicate with said body oflubricant in all positions of rotation of said plug and the other two ofsaid grooves being shorter than said one longitudinal groove with bothterminating short of opposite ends of the plug and being adapted toextend between and interconnect aligned pairs of upper and lower dwarfgrooves in the fully open and fully closed positions of the plug, saidother two grooves being substantially equally spaced from said onegroove an angular distance greater than 90 and being disposed atopposite sides of the plug port from each other, and the circumferentialspacing between three successive pairs of said dwarf body grooves beingthe same and equal to the circumferential spacing between said long pluggroove and each of said short plug grooves.

4. In a plug valve assembly characterized by a through fluid flowpassage intersected by a plug seating bore having an axis offsetlaterally Wit-h respect to the axis of said passage, a plug having anoffset port therethrough rotatably mounted in said bore for movementbetween a fully closed position where the plug blocks fluid flow throughsaid passage and a fully open position where the plug port is alignedwith said passage, means providing a body of lubricant in said boreadjacent one end of the plug in the assembly, four circumferentiallyspaced dwarf grooves in the surface of said bore at said one end all incommunication with said body of lubricant, two of said dwarf groovesbeing located on the same side of said passage and spaced an angulardistance equal to the angle of rotation of the plug between open andclosed valve positions, said angle being greater than 90 and the othertwo dwarf grooves being located at the other side of said passage andspaced less than said distance, a similar plurality of dwarf grooves atthe other end of said bore, circumferential grooving in the seatingsurface of the plug and body at said other end of said bore connectingall of said lower dwarf grooves, and three circumferentially spacedlongitudinal grooves on the surface of said plug, one of saidlongitudinal grooves being long enough to communicate with said body oflubricant in all positions of rotation of said plug and the other two ofsaid grooves being shorter than said one longitudinal groove with bothterminating short of opposite ends of the plug and being adapted toextend between and interconnect aligned pairs of upper and lower dwarfgrooves in the fully open and fully closed positions of the plug, 'andsaid short grooves being circumferentially spaced said angular distancefrom said long groove and being disposed at opposite sides of said plugbore.

' 5. In the plug valve assembly defined in claim 4, said 'plug portbeing offset in said plug in the opposite direction from the offset ofsaid plug bore axis relative to the passage, and said long groove movingalong only a closed surface of said bore during rotation of the plugbetween fully open and fully closed positions.

6. In a plug valve assembly characterized by a through fluid flowpassage intersected by a tapered plug seating bore having an axis offsetlaterally with respect to the axis of said passage, a tapered plughaving an offset port rotatably mounted in said bore for movementbetween a fully closed position where the plug blocks fluid flow throughsaid passage and a fully open position where the plug port is alignedwith said passage, means providing a body of lubricant in said boreadjacent the smaller end of the plug in the assembly, fourcircumferentially spaced dwarf grooves in the surface of said bore atsaid smaller end all in communication with said body of lubricant, foursimilar dwarf grooves at the larger end of said bore, circurnferentialgrooving in the seating surface of said plug and body at said other endof said bore connecting all of said lower dwarf grooves, and threecircumferen-tially spaced longitudinal grooves on the surface of saidplug, one of said plug grooves being long enough to communicate withsaid body of lubricant in all positions of rotation of said plug and theother two of said grooves being substantially equally circumferentiallyspaced from said one longitudinal groove be an angular distance greaterthan 90 and being shorter than said one longitudinal groove with bothshort plug grooves terminating short of opposite ends of the plug andbeing adapted to extend between and interconnect aligned pairs of upperand lower dwarf grooves in the fully open and fully closed positions ofthe plug, said plug and dwarf grooves being so circumferentially spacedthat in the fully open position of said valve the long plug groove andone short plug groove are so connected with the body grooves as to forma continuous circuit of lubricant around the passage opening into oneside of the bore, and in fully closed position of said valve the longplug groove and the other short plug groove are so connected to the bodygrooves that a complete circuit of lubricant is formed around thepassage opening into the other side of the bore.

7. In the plug valve defined in claim 6, said port being offset in saidplug in the opposite direction from the olfset of said plug axisrelative to the passage, and said short plug grooves each being spacedmore than 90 from said long plug groove.

8. A tapered plug for use in a lubricated plug valve assembly, said plughaving an external surface of revolution about a central axis, a portextending straight through said plug with its axis at right angles tobut laterally olfset with respect to said central axis, and threelongitudinal surface grooves on said plug, two of said grooves being ofsubstantially the same length and shorter than and substantiallyequisdistantly spaced circumferentially from the other longer groove byan angle greater than 90, one of said short grooves and the longergroove being located adjacent opposite sides of one end opening of theport to 'said surface, and the other short groove being located adjacentthe other end opening of said port and being on the same side as saidlonger groove, a circumferential groove at the larger end of said plugspaced from all of said longitudinal grooves, and the longerlongitudinal groove extending further toward the smaller end of saidplug than the shorter grooves.

9. In the plug defined in claim 8, a circumferential groove extendingaround the small end of the plug connected to the long groove but spacedfrom the short grooves.

10. In the plug defined in claim 8, said long groove extending to thesmall end of the plug and said short grooves both terminating short ofsaid small end of the plug.

References Cited by the Examiner UNITED STATES PATENTS 2,145,628 1/1939Milliken 137-246.22 X 2,391,278 12/ 1945 Stark 251-175 2,608,374 8/1952Morehead 137246.14 2,658,713 11/1953 Scherer l37-246.18 2,900,995 8/1959 Dickerson et al. 1-372-46 .18 X 2,931,380 4/ 1960 Mueller et al 137246.l4 2,997,056 8/ 1961 Massey 137-246.15

FOREIGN PATENTS 453,188 12/ 1948 Canada.

I WILLIAM F. ODEA, Primary Examiner.

ISADOR 'WEIL, Examiner,

D. ROWE, C. GORDON, Assistant Examiners.

1. IN A PLUG VALVE ASSEMBLY CHARACTERIZED BY A THROUGH PASSAGE FOR FLUIDFLOW INTERSECTED BY A PLUG SEATING BORE, A PORTED PLUG ROTATABLY MOUNTEDIN SAID BORE FOR MOVEMENT BETWEEN A FULLY CLOSED POSITION WHERE ITBLOCKS FLUID FLOW THROUGH SAID PASSAGE AND A FULLY OPEN POSITION WHERETHE PLUG PORT IS ALIGNED WITH SAID PASSAGE, THE AXIS OF ROTATION OF SAIDPLUG BEING LATERALLY OFFSET WITH RESPECT TO THE AXIS OF SAID PASSAGE,AND SAID PLUG HAVING A STRAIGHT THROUGH PORT THE LONGITUDINAL AXIS OFWHICH IS OFFSET WITH RESPECT TO THE AXIS OF ROTATION OF SAID PLUG TOALIGN SAID PORT WITH SAID PASSAGE IN VALVE OPEN POSITION, MEANSPROVIDING A BODY OF FLUENT LUBRICANT IN SAID ASSEMBLY, A SYSTEM OFGROOVING IN THE SEATING SURFACES OF SAID PLUG AND BODY EXTENDINGCONTINUOUSLY AROUND THE INTERSECTION OF SAID PASSAGE AND BORE AT LEASTAT ONE SIDE OF SAID BORE IN BOTH FULLY OPEN AND FULLY CLOSED POSITIONSOF SAID PLUG, SAID SYSTEM COMPRISING THREE CIRCUMFERENTIALLY SPACEDLONGITUDINAL GROOVES IN THE PLUG SURFACE, ONE OF SAID GROOVES BEINGLARGER THAN THE OTHER TWO AND CONTINUOUSLY CONNECTED IN COMMUNICATIONWITH SAID LUBRICANT BODY AND THE OTHER TWO GROOVES BEING DISCONNECTEDFROM COMMUNICATION WITH SAID LUBRICANT BODY EXCEPT IN VALVE OPEN ANDCLOSED POSITIONS OF THE PLUG, SAID OTHER TWO GROOVES BEING DISPOSED ATOPPOSITE SIDES OF THE PLUG PORT FROM EACH OTHER AND BEING EQUALLYCIRCUMFERENTIALLY SPACED RELATIVE TO SAID LONGER GROOVE AN ANGULARDISTANCE GREATER THAN 90*, MEANS CONNECTING SAID SYSTEM TO RECEIVELIBRICANT FROM SAID BODY OF FLUENT LUBRICANT, AND MEANS FOR INTERRUPTINGTHE CONTINUITY OF SAID SYSTEM OF GROOVING AS THE PLUG IS ROTATINGBETWEEN SAID POSITIONS.